(Balaenoptera musculus) (adult)The tongue of a Blue Whale can weigh up to 3 tons. Despite their tremendous size, blue whales feed almost exclusively on tiny crustaceans called krill and cannot swallow anything much larger than a beach ball.

(for Black rhinoceros, Diceros bicornis) (Adult, male)An adult black rhinoceros weighs between 2.30 tons. Rhinoceros are extremely aggressive — nearly one of every two males will die as a result of fighting with other rhinoceros.

In other words, 3 tons is 0.7260 times the weight of a Hippopotamus, and the weight of a Hippopotamus is 1.380 times that amount.

(Hippopotamus amphibius) (adult, male)The average weight of an adult male hippopotamus ranges from 4.130 tons. Appearances to the contrary, adult hippos cannot swim or float in water; they actually move by leaping and walking across lake bottoms at about 8 kph (5 mph).

In other words, 3 tons is 0.430 times the weight of a Tyrannosaurus rex, and the weight of a Tyrannosaurus rex is 2.30 times that amount.

(for FMNH PR2081, a.k.a. "Sue") (a.k.a. Tyrannosaurus, a.k.a. T-Rex) (estimated live weight)The notable Tyrannosaurus specimen housed at the Field Museum of Natural History in Chicago, Illinois, "Sue," is estimated to have weighed about 7.10 tons while alive. A renowned predator in popular culture, the teeth of tyrannosaurus rex were up to 33.02 cm (13 in) long.